The present invention relates to a mounting device for a guiding bolt of a floating-caliper spot-type disc brake.
In conventional brakes of this type, the guiding between the caliper and carrier components is formed by at least one guiding bolt sliding in a bore of one of the components and by a guiding element spaced in circumferential direction from the guiding bolt. Then, a recess may be provided for the accommodation of the threaded end portion of the guiding bolt, such recess being continuous in the direction of the axis of the guiding bolt and being slotted over its entire axial length and transverse width towards the periphery of the one component. In this construction, a nut is threaded onto the end portion of the guiding bolt to clamp the guiding bolt to the component provided with the recess when tightened. The position of the slot is such as to permit the removal of the caliper component from the carrier component after loosening the nut.
In a floating caliper spot-type disc brake the caliper component embraces the brake disc like a U and includes a hydraulically actuatable piston which directly actuates the associated brake shoe which is situated on one side of the brake disc. The brake shoe disposed on the opposite side of the brake disc is indirectly urged against the brake disc as a result of the displacement of the caliper component in relation to the brake carrier component. The guiding of the caliper is effected by means of one or of several guiding bolts which are fastened to one of the two components, that is, either to the caliper component or to the carrier component. When replacing the brake shoes, this mounting arrangement will be disengaged and the caliper component will be moved relative to the carrier component to assume a position which affords easy access to the brake shoes to be replaced.
A disc brake of this type is described in German patent No. 26 49 627, wherein the caliper component is guided by means of two guiding bolts slidable in bores of the caliper component. Screw couplings serve to fasten the guiding bolts to the brake carrier component. One guiding bolt includes at its end a threaded step extending through a recess of the brake carrier component and having a nut threaded thereunto, so that the guiding bolt will be fastened to the brake carrier component after tightening of this nut. The recess receiving the one guiding bolt is slotted and open towards the edge of the brake carrier component so as to make it possible to pivot the caliper component together with the one guiding bolt about the other guiding bolt after loosening of the fastening nut. Following the exchange of brake shoes with the caliper component swung upwards, the caliper component will be swivelled to its former position and the guiding bolt will be secured in the recess of the brake carrier component by tightening the nut. It has to be regarded as particularly disadvantageous in this known device that the guiding bolts are not secured against turning about their longitudinal axes; this allows disengagement of the threaded couplings during operation. In addition, it is rendered difficult if not impossible to tighten the nut, since, due to the presence of a seal surrounding the accessible portion of the bolt, there is no chance to prevent joint rotation of the bolt with the nut by retaining the bolt during the tightening of the nut.